The best theoretical upload likely if you have a Verizon FIOS account (better than cable modem) is 20 Mega-bits per second; about 2.5 MB per second.
My math yields 6.6 min. per GB, or 55 hrs per drive. 22 days for 10 drives. That's if you can get the full upload speed, which is unlikely.

I use 2 backups. I have a 500 gig raid stripe 0 (2-250 gig drives). I then have retrospect launch at 4am in the morning and back up the raid to a 1 gig firewire drive. It only updates any new items. Finished projects go into a 160 gig partition on a 3rd drive. When that is full I write a tape backup using the VXA-320 firewire Data Tape back up system so they are archived.

I have used this method for 18 months now and at my work flow level I write a tape 1 time a month.

If you are looking for best Free Online Backup service then you should try myPCBackup since my hard drive crashed and I lost all my family photos and precious data. Thankfully I had my computer backed up online with MyPCBackup and I was able to quickly recover everything.